Computerized tomography (CT) has developed as a powerful diagnostic tool affording a surgeon detailed imagery as to the location of abnormal tissue intended to be incised. CT scanning is typically performed as a diagnostic in response to clinical manifestations of disease such as neurological disorders. CT scanning is also used in the context of pre- and post-surgical evaluations to assess the location and size of an abnormal tissue mass, and the success of the abnormal tissue mass incision, respectively. When post-surgical CT scanning is performed during surgical recovery, the discovery of a residual abnormal tissue mass requires the scheduling of an additional surgical procedure. With current conventional procedures and equipment, CT scanning performed while a patient is still under surgical anesthesia requires the transport of the patient to a CT scanning facility thereby compromising surgical field sterility and risking injury to the anesthetized patient.
As CT scanning allows for earlier diagnosis and more complete assessment as to an abnormal tissue mass, a physician is better able to assess a favorable outcome for a surgical intervention as compared to radiation or chemotherapeutic treatments. While irregularly shaped, deeply situated or multiple abnormal tissue masses were previously likely to be deemed inoperable, technological advances involving position sensing surgical aids such as catheters and robotically controlled surgical instruments will increasingly allow for successful complex surgical interventions. The usage of position sensing surgical instruments requires a reference frame within the patient's body relative to the fixed components of the surgical aid. Once a frame of reference exists, a catheter or other position sensing surgical aid is free to navigate a preselected pathway to a desired location within the body of a patient, thereby allowing access to body tissues which would otherwise not be accessible through line of sight manual surgical techniques.
Owing to the limitations in current applications of CT scanning, there exists a need for CT scanning to be performed while an anesthetized surgical patient lies on an operating table. Such a CT scanning system affords a surgeon instant feedback as to the success of abnormal tissue excision and with less likelihood of surgical field contamination. Further, such a system would provide a standard frame of reference between a body tissue and position sensing surgical aids.